[PATCH 12/14] x86/entry: Rename trace_hardirqs_off_prepare()

Peter Zijlstra
2020-05-29T21:34:59Z

The typical pattern for trace_hardirqs_off_prepare() is:

ENTRY
lockdep_hardirqs_off(); // because hardware
... do entry magic
instrumentation_begin();
trace_hardirqs_off_prepare();
... do actual work
trace_hardirqs_on_prepare();
lockdep_hardirqs_on_prepare();
instrumentation_end();
... do exit magic
lockdep_hardirqs_on();

which shows that it's named wrong, rename it to
trace_hardirqs_off_finish(), as it concludes the hardirq_off
transition.

Also, given that the above is the only correct order, make the
traditional all-in-one trace_hardirqs_off() follow suit.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/entry/common.c | 6 +++---
arch/x86/kernel/cpu/mce/core.c | 2 +-
arch/x86/kernel/nmi.c | 2 +-
arch/x86/kernel/traps.c | 4 ++--
include/linux/irqflags.h | 4 ++--
kernel/trace/trace_preemptirq.c | 10 +++++-----
6 files changed, 14 insertions(+), 14 deletions(-)

--- a/arch/x86/entry/common.c
+++ b/arch/x86/entry/common.c
@@ -65,7 +65,7 @@ static noinstr void enter_from_user_mode

instrumentation_begin();
CT_WARN_ON(state != CONTEXT_USER);
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
instrumentation_end();
}
#else
@@ -73,7 +73,7 @@ static __always_inline void enter_from_u
{
lockdep_hardirqs_off(CALLER_ADDR0);
instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
instrumentation_end();
}
#endif
@@ -569,7 +569,7 @@ bool noinstr idtentry_enter_cond_rcu(str
lockdep_hardirqs_off(CALLER_ADDR0);
rcu_irq_enter();
instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
instrumentation_end();

return true;
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1915,7 +1915,7 @@ static __always_inline void exc_machine_
* that out because it's an indirect call. Annotate it.
*/
instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
machine_check_vector(regs);
if (regs->flags & X86_EFLAGS_IF)
trace_hardirqs_on_prepare();
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -330,7 +330,7 @@ static noinstr void default_do_nmi(struc
__this_cpu_write(last_nmi_rip, regs->ip);

instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();

handled = nmi_handle(NMI_LOCAL, regs);
__this_cpu_add(nmi_stats.normal, handled);
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -634,7 +634,7 @@ DEFINE_IDTENTRY_RAW(exc_int3)
} else {
nmi_enter();
instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
if (!do_int3(regs))
die("int3", regs, 0);
if (regs->flags & X86_EFLAGS_IF)
@@ -854,7 +854,7 @@ static __always_inline void exc_debug_ke
{
nmi_enter();
instrumentation_begin();
- trace_hardirqs_off_prepare();
+ trace_hardirqs_off_finish();
instrumentation_end();

/*
--- a/include/linux/irqflags.h
+++ b/include/linux/irqflags.h
@@ -32,7 +32,7 @@

#ifdef CONFIG_TRACE_IRQFLAGS
extern void trace_hardirqs_on_prepare(void);
- extern void trace_hardirqs_off_prepare(void);
+ extern void trace_hardirqs_off_finish(void);
extern void trace_hardirqs_on(void);
extern void trace_hardirqs_off(void);
# define lockdep_hardirq_context(p) ((p)->hardirq_context)
@@ -101,7 +101,7 @@ do { \

#else
# define trace_hardirqs_on_prepare() do { } while (0)
-# define trace_hardirqs_off_prepare() do { } while (0)
+# define trace_hardirqs_off_finish() do { } while (0)
# define trace_hardirqs_on() do { } while (0)
# define trace_hardirqs_off() do { } while (0)
# define lockdep_hardirq_context(p) 0
--- a/kernel/trace/trace_preemptirq.c
+++ b/kernel/trace/trace_preemptirq.c
@@ -58,7 +58,7 @@ NOKPROBE_SYMBOL(trace_hardirqs_on);
* and lockdep uses a staged approach which splits the lockdep hardirq
* tracking into a RCU on and a RCU off section.
*/
-void trace_hardirqs_off_prepare(void)
+void trace_hardirqs_off_finish(void)
{
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
@@ -68,19 +68,19 @@ void trace_hardirqs_off_prepare(void)
}

}
-EXPORT_SYMBOL(trace_hardirqs_off_prepare);
-NOKPROBE_SYMBOL(trace_hardirqs_off_prepare);
+EXPORT_SYMBOL(trace_hardirqs_off_finish);
+NOKPROBE_SYMBOL(trace_hardirqs_off_finish);

void trace_hardirqs_off(void)
{
+ lockdep_hardirqs_off(CALLER_ADDR0);
+
if (!this_cpu_read(tracing_irq_cpu)) {
this_cpu_write(tracing_irq_cpu, 1);
tracer_hardirqs_off(CALLER_ADDR0, CALLER_ADDR1);
if (!in_nmi())
trace_irq_disable_rcuidle(CALLER_ADDR0, CALLER_ADDR1);
}
-
- lockdep_hardirqs_off(CALLER_ADDR0);
}
EXPORT_SYMBOL(trace_hardirqs_off);
NOKPROBE_SYMBOL(trace_hardirqs_off);